If the JW water valve solution does not keep the line from freezing and it will works most of the time.. there is a
water line heater kit 4389174
the insulation around the tube has broken down or has a air gap.. causing poor insulation valve around the tub
BTW the fill tube does pull out..Just release the fitting from the back and pull the black part from inside the freezer...down then out....it is a lot harder to get it back in...
Fill Tube Part # 4389174